Telephone system.



C. L. GOODRUM.

TELEPHONE SYSTEM.

APPLICATION FILED JUNE 15, 1916- 1 27 6, 52 1 Patented Aug. 20, 1918.

2 SHEETSSHEET C. L. GOODRUM.

TELEPHONE SYSTEM.

APPLICATION FILED JUNE 25. 1916.

1 ,276,52 1 Patented Aug. 20, 1918.

2 SHEETSSHEET. 2-

ln men for: C haw/es L. Goodrum.

by Airy.

WEE

STATE% FATENT CHARLES L. GOODRUM, OF NEVJ YORK, N. Y., ASSIGNOR TO WESTERN ELECTRIC COIK- PANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK;

TELEPHONE SYSTEM.

Application filed June 15, 1916.

To all whom it may concern Be it known thatI, CHARLES L. Goonmm, a citizen of the Unitecl.States, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to tw0-wire mul tiple automatic telephone systems of the character described in Patent No. 1,251,503, granted to me January 1, 1918 and relates particularly to an arrangement for registering the number of telephone conversations which take place on a given telephone line in such a system.

The object of the invention is to provide an arrangement of 'this character in which the operation of the message register appropriated to a telephone line may be controlled in a simple and reliable manner and without hindrance to the talking currents in the lines.

In accordance with a feature of the invention, a controlling magnet of the message register is normally bridged between a talking conductor of the telephone line to which it is appropriated and the source of power through which the apparatus of the exchange is actuated and so arranged that it will offer no impedance to the talking currents.

The invention will be more fully understood from the following detailed description of the system and the drawings, in which Figure 1 shows the invention applied to a system, employing an automatic switch for extending the telephone line to a connecting circuit. Figs. 2 and 3 are modified forms of the invention applied to systems similar to that shown in Fig. 1.

In the modification shown in Fig. 1, the apparatus and circuits are designated by the same reference numerals as used to designate similar apparatus in the application to which reference has been made. The line relay is shown at 1, test relay at a, cut-off relay at 2i, the line finder brushes and terminals at 20, 21, and 20, 21, the side-switch arms at 7, 12, 13 and H, side-switch magnet at 11, and the motor magnets 01' the line finder at 9 and 16. It is thought that the invention will be best understood by describing the operation in extending a call and in registering such call, provided it success Specification of Letters Patent.

latented Aug. 26, 1218.

Serial No. 103,854.

ful. As the operation of the apparatus for extending the call to the line of the called subscriber is described in detail in the patcut above referred to, the operation, with the exception of that part which has to do with the operation of the message register, will not be described in detail, but will be merely outlined.

Assuming that the subscriber shown at the left of Fig. 1 removes his receiver from the hook and initiates a call, line relay 1 will operate, closing a circuit for the relay 2, causing it to operate. In response to the operation of relay 2, a circuit is closed for stepping magnet 9 over the side-switch arm 7 in position 1, which causes such magnet to step the brushes around until the test brush 10 encounters a contact 5 that is individual to the group of lines in which the calling line appears in the terminals of the line finder switch.

W hen contact 10 makes contact with the terminal 5, magnet 11 of the side switch is energized, and the side switch is moved into its second position, in which position the stepping magnet 16 is energized over the back contact of relay l, and the magnet 11 of the side switch is also energized over acircuit including the relay 3, front contact of relay 2 and back contact of relay 4. The energization of the magnet 11 at this time does not move the side-switch arms, and the side switch remains in position 2.

In response to the operation of the stepping magnet 16, the brushes 20 and 20 move over terminals 21 and 21, until the particular terminals 21 and 21 are reached which are individual to the calling line, when a circuit will be closed from a source of alternating current 18, through the test relay i,

front contact and right-hand armature of line relay 1, upper winding of relay 25, terminal 21, contact 20, side-switch arm i l, in position 2, condenser 22, resistance 23 to ground. The register magnet indicated pt 25 is provided with two windings which are differentially arranged on the core, the arrangement being such that current through either winding alone will notmagnetize the core sufliciently to attract the magnet armature, nor will current in both windings magnetize the core sufiiciently unless the current flow in both windings is in such a direction that the magnetic etfects produced thereby aid each other.

of the side switch, a circuit is established for tl e cut-cit "clay 2%, which may be traced as follows: ba'tery lower windin of the register magnet 2* cut-oil re w Y terminal 521 contac 2 s det-rnce switch arm 13 in posi ion 3, resis l ooerate grouiid. Th cut-oil elay 2% wil hut the magnet will not opera'c the lower winding thereof is energized this cir nit. T11 response to the actia the impulse sende at the calling ers station the connection may be eiit nded o'iracts of the called subscribers line of au'oinatic switches which are wn, but which may be or any usual cion but are prterably of the con shown in aeplicants prior applilt may be noted that ig'h the impulses for controlling the i 1 of the selector switches pass 'h the upper winding of the register I while current is also flowing in e lowe" winding thereof, the register inagj net will not operate as the magnetizing efof the windings under these circumstances are opposed The operation of testing and ringing takes pl; co in the usual manner and will not be described in detail. ll hen the called sub scriber answers, apparatus associated with the sole switches used in establishing connection will operate, and *ill connect a source or poteitiil on the upper conductor a. This agpar tus may he in the form of a relay or an utoinatic switcln such as a le switc which operates in response to the act or the calling party answering the ll hen battery is connected to conduc ablish d over such conby way of 1 -switch arin ii in posion contact 20 terminal 21, upper wind mg of register magnet 25, lower armature and front Contac of cut-oil relay Q-l over l a subscribers substation us, tlienco b line front contact or" cut-off relay to ter- ,inch arin lo i around. Uncle ergized, and as tlre inected to line con- 65 ductoru ha; been chosen so that the two windings under these circumstances will assist one another, the register magnet. 25 will be energized and will operate a suitable counting train to register the call. ll' hen the magnet operaubes the armature the conn ction established will not atl ect the registration of the call.

The modification shown in Fi differs from that shown in Fig. 1 in that the regisr magnetitseli is not included in the tall; l conductor. but is controlled by apolarized relay indicated at 30, which is included *1 one of the talking conductors and which ll if: adapted to be shunted out of the talking conductor by the ope ation of the register inae'net The 0 r ae ation of the line finder is identically tlie seine in the modification shown in Fig.2. 1, and will not be described. There fore it will be assumed the the line finder has found the terminals of the calling line and that the side-switch arms 13 and 14 are in position in which position a circuit is closed from battery left-hand winding of register magnet 25, cut-oft relay 2%, polarized relay 30, contacts 21 and 20, sideswitch arm 13 resistance to'g'round. The cut-off relay will he energized but the magnet will notbe energized, as current is flowing through only one winding thereof, and the polarized rela} 30 will not be enered due to lo polarity of the current flowployed in 1 a, ueled age-arii circuit wi l hcrerore be established from such source ot oteutial through the conductor to arm 1%. contact 20, terminal 21,

out contact and upper armature of cutoa'; re Z-l, conductor 1 to the subscribers substation to conductor 2 and lower zrinature and trout contact of cut-oil role i l, polarized :ela 30, terminal :21. contact E20,

*esistance to ground.

: impulse of the polarity required polcrize: relay will pass over traced and hence through the winding of the polarized relay 30, which will operate. The operation of the polarized relay 3O closes a circuit from battery 35 to the right-hand winding of the magnet 25, through the armature of polarized relay 30 to ground. Both windings of the magnet 25 are now energized, and, due to their arrangement on the core, their effect will be cumulative so that the magnet 25 will be energized, and, in attracting its armature, will close at its front contact a shunt around the polarized relay 30, thus shunting such relay 30 from the talking circuit. Upon the deenergization of the relay 30, due to its shunting by the magnet 25, the magnet will still hold its armature in its attracted position, due to the fact that the circuit through the left-hand winding thereof is still established, and the energization of such winding is suflicient to hold the armature, once it has been attracted.

In the modification shown in Fig. 3, the appa atus individual to the line and the line finder switch is arranged identically as in the modification shown in Fig. 1, with the exception that the side-switch magnet 11 is provided with an armature and contact for a purpose which will hereinafter appear. In this modification, the register magnet is not provided with a separate holding winding. A polarized relay 30 is also employed, but in this case it is not connected at any time in the talking circuit. In this modification, as in Fig. 1, the line finder operates, and when the terminal 21 and contact 20 are brought into connection, the side-switch arms 14, 13, 12 and 7 are moved to position In position 3 of the side switch, a circuit is established from the battery 35, through the register magnet 25. cut-off relay 2%, terminal 21, contact 20, side-switch arm 13 in position 3, resistance 23 to ground. The cut-off relay 2-1 will be energized over this circuit, but the resistance 23 is so adjusted that there will not be sufficient current flowing in the circuit to operate the register magnet 25. However, when the connection has been established and the called subscriber answers, a source of potential of the polarity required to operate the polarized relay 30 will be placed upon the conductor a by apparatus associated with the selector switches used in establishing the connection. A circuit may therefore be traced from such source of potential through the conductor (I, polarized relay 30, side-switch arm 11, position 3, contact 20, terminal 21, lower armature and front contact of cut-off relay 2%, conductor 1, subscribers station, conductor upper armature and front contact of relay 2 1, terminal 21, contact 20, sideswitch arm 13, position 3, resistance 23 to ground. The operation of the polarized relay shunts the resistance 23 from the energizing circuit of the magnet 25', in series with the cut-off relay 2%, previously traced, so that the energizing circuit for the register magnet 25, may now be traced as follows: battery 35, register magnet 25, cut-off relay 2st, terminal 21, contact 20, side-switch arm 13, position 3, side-switch arm 6, position 3, armature of polarized relay 30 to ground.

A circuit is also closed for the magnet 11 of the side-switch which may be traced from battery, magnet 11, side-switch arm 12 in position 3, armature and back contact of relay 11, side-switch arm 6, position 3, armature and contact of polarized relay 30. The magnet 11 will energize, and in energizing break its energizing circuit, and as a result of this operation the side switch will be moved into position at, which is the through or talking position.

iltlthough in position 1 the shunt to ground about the resistance is removed at the arm 6, there will still be sufficient current flowing through the magnet 25 to maintain its armature attracted so that the register magnet 25 will remain energized until disconnect takes place.

\Vhat is claimed is:

1. In a telephone system, a telephone line, a message register for recording calls on said line, an electromagnet for controlling the operation of said register, a cut-off relay, means for operating said electromagnet independent of said cut-oft relay, and a series holding circuit for said electromagnet and said cut-off relay.

2. In a telephone system, a telephone line, a message register for recording calls on said line, a pair of electromagnet coils for controlling said register, and circuits for said coils, one extending through the contact of said cut-01f relay and the other through the winding of said cut-off relay.

In a telephone system, a telephone line, a message register for recording calls on such line, an electromagnet for controlling the operation of said register, an automatic switch provided with a pair of brushes for extending said calling line to a connecting circuit, and an energizing and holding circuit for such electromagnet including one of such pairs of brushes.

i. In a telephone system, a telephone line, a message register for recording calls on said line, an electromagnet for controlling the operation of said register, an automatic switch provided with brushes for extending said. calling line to a connecting circuit, a

cut-off relay, and a series holding circuit for I s brushes coooerate his in s t a 1' a sociated cat-otl relay and means in said con;iecting eirciiit for eontrollin; the operation or said -l 3. In 2. t 1 .J ralit f therefor, a tat-ts in which movable message regi snbscribers' lines of said mess operation then its Winding i i, L r assotiatetl comprising two phone s isteim the combination me he switches for line l electrical ratio of a mes 1 bridge 7 L talking coir aid line and said source aiio means control able over said line tor a tuating said registe 10. In a telephone system, the combination with a telephone line, flLl'tOlmiilC s provided with two bras and a tii'o-ii'ire multiple bank of terminals with W:

for extending electrical enerp' i'or ies ot a message for L and a source said swite Genie: o

King conductors, a source means for extending er bridged bet-Ween egg conductors and said means independent of the tall:-

said line for operating said n V 7 but (/3. Alex l a telephone system, a telephone line tn 7 talking conductors, a source means for extending 'ster bridged between said li a me i,\\4 S one of said "1C actors and said soni act-ea ing said regiss2 id line. system, a teleohone line g conductors, a trunk energy, means for Ujlk line, a messone oft said sourc and i *stem. a telephone line .an-is ng two tall; I conductors, a trunk a source oi? electrical energy, means iding said line a message register between one of said tall'ing eondnctors and said source, and means included in said trunk line for actuating said register subsequent to the extension of said line.

l5. 3 i a tele hone system. telephone lines each coniorisingz two talking conductors, a

source of electrical energy common to said l; noon to said lines for extendsa'd lines a message register individual to each of said lines bridged between a tall;- ing conductor t the associated line and said source and towns common to said lines for lasing the :tuation of said message regis- 

